1. Field of the Invention
The invention relates generally to a method of manufacturing an aluminum oxide film in a semiconductor device. More particularly, the invention relates to a method of manufacturing an aluminum oxide film in a semiconductor device, which can increase the growth rate of an aluminum oxide layer and can also improve prevention of penetration of hydrogen into an underlying layer or an aluminum oxide (Al2O3) film.
2. Description of the Prior Art
A process of forming an aluminum oxide film by atomic layer deposition method includes sequentially exposing an aluminum source gas and an oxygen gas to a substrate, while a substrate is maintained at a constant temperature, i.e., from 200xc2x0 C. to about 450xc2x0 C. TMA is used as a conventional aluminum source gases and H2O is used as a reactive gas.
A method of manufacturing an aluminum oxide film in a conventional semiconductor device will be below explained by reference to FIG. 1.
Referring now to FIG. 1, a process of forming an aluminum oxide (Al2O3) film includes a supply step of an aluminum source (A1), a first purge step (B1), a supply step of oxygen reactive gas (C1) and a second purge step (D1). One cycle consists of the four steps (A1, B1, C1 and D1). First, in order to form an aluminum oxide (Al2O3) film using an atomic layer deposition method, a semiconductor substrate is mounted into the reactor in which an exhaust pump is equipped and is maintained at the temperature range of 200xc2x0 C. to about 450xc2x0 C.
In the supply step of an aluminum source (A1), TMA, being an aluminum source, is supplied into the reactor for 0.1 second to 3 seconds, so that aluminum (A1) can be adhered to the surface of the semiconductor substrate.
In the first purge step (B1), in order to remove un-reacted aluminum source gas and reaction by-products, a N2 gas is implanted for 0.1 second to 3 seconds or is vacuum-purged to exhaust via the exhaust pump.
In the supply step of oxygen gas (C1), oxygen reaction gas is supplied in the reactor for 0.1 second to 3 seconds, so that oxygen (O) can be adhered to the surface of the semiconductor substrate.
In the second purge step (Dl), in order to remove un-reacted oxygen reaction gas and reaction by-products, a N2 gas is implanted for 0.1 second to 3 seconds or is vacuum-purged to exhaust via the exhaust pump.
In order to form an aluminum oxide film to a desired thickness, the four steps forming one cycle are repeatedly performed until a desired thickness is attained.
Because the deposition rate is slow in view of atomic layer deposition method, when being applied to a mass production process, the method described in FIG. 1 is disadvantageous in terms of cost and further a conventional aluminum oxide film is not provided to prevent any diffusion of hydrogen atoms.
A method of manufacturing an aluminum oxide film in a semiconductor device is disclosed which can increase the growth rate of an aluminum oxide film and which can improve the characteristics thereof by prohibiting penetration of hydrogen. By supplying a NH3 activation gas simultaneously with an aluminum source gas in a supply step of an aluminum source, the disclosed method prevents any degradation of electrical characteristics of the layer overlying an aluminum oxide film and improves the electrical characteristics of the semiconductor device.
One disclosed method of manufacturing an aluminum oxide film in a semiconductor device is characterized in that it comprises a first step of simultaneously supplying an aluminum source gas and an activation gas into a reactor via individual lines in which a substrate is mounted; a second step of removing un-reacted aluminum source and reaction by-products from said reactor; a third step of supplying oxygen reaction gas into the reactor; a fourth step of removing un-reacted oxygen gas from the reactor; and a fifth step of repeatedly performing the first step through the fourth step constituting one cycle for depositing an aluminum oxide film to thus form the aluminum oxide film.
In the above step, the reactor is maintained at the temperature ranging from about 200xc2x0 C. to about 450xc2x0 C.
The aluminum source is supplied into the reactor using TMA or MTMA for a time period ranging from about 0.1 second to about 3 seconds.
The activation gas is NH3 gas and is supplied into the reactor at a flow rate ranging from about 10 sccm to about 500 sccm for a time period ranging from about 0.1 second to about 3 seconds.
The second step or the fourth step purges the reactor by supplying N2 gas for a time period ranging from about 0.1 second to about 3 seconds.
The oxygen reaction gas is supplied in to the reactor using H2O vapor for a time period ranging from about 0.1 second to about 3 seconds.
The aluminum oxide film can be formed by supplying the NH3 activation gas in the second step or the fourth step instead of supplying in the first step.
Another method of manufacturing an aluminum oxide film in a semiconductor device is characterized in that it comprises a first step of supplying an aluminum source into a reactor in which a substrate is mounted; a second step of removing un-reacted aluminum source and reaction by-products from the reactor; a third step of supplying oxygen reaction gas and an activation gas into the reactor; a fourth step of removing un-reacted oxygen gas from the reactor; and a fifth step of repeatedly performing the first step through the fourth step constituting one cycle for depositing an aluminum oxide film to thus form the aluminum oxide film.
The reactor is maintained at the temperature ranging from about 200xc2x0 C. to about 450xc2x0 C.
The aluminum source is supplied into the reactor using TMA or MTMA for a time period ranging from about 0.1 second to about 3 seconds.
The activation gas is NH3 gas and is supplied into the reactor at a flow rate ranging from about 10 sccm to about 500 sccm for a time period ranging from about 0.1 second to about 3 seconds.
The second step or the fourth step purges the reactor by supplying N2 gas for a time period ranging from about 0.1 second to about 3 seconds.
The oxygen reaction gas is supplied in to the reactor using H2O vapor for a time period ranging from about 0.1 second to about 3 seconds.
The NH3 activation gas is supplied in the second step or the fourth step instead of supplying NH3 in the third step.